'\" et
.TH PTHREAD_EQUAL "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
pthread_equal
\(em compare thread IDs
.SH SYNOPSIS
.LP
.nf
#include <pthread.h>
.P
int pthread_equal(pthread_t \fIt1\fP, pthread_t \fIt2\fP);
.fi
.SH DESCRIPTION
This function shall compare the thread IDs
.IR t1
and
.IR t2 .
.SH "RETURN VALUE"
The
\fIpthread_equal\fR()
function shall return a non-zero value if
.IR t1
and
.IR t2
are equal; otherwise, zero shall be returned.
.P
If either
.IR t1
or
.IR t2
are not valid thread IDs, the behavior is undefined.
.SH ERRORS
No errors are defined.
.P
The
\fIpthread_equal\fR()
function shall not return an error code of
.BR [EINTR] .
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
Implementations may choose to define a
thread ID as a structure. This allows additional flexibility and
robustness over using an
.BR int .
For example, a thread ID could include a sequence number that allows
detection of ``dangling IDs'' (copies of a thread ID that has been
detached). Since the C language does not support comparison on
structure types, the
\fIpthread_equal\fR()
function is provided to compare thread IDs.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIpthread_create\fR\^(\|)",
.IR "\fIpthread_self\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<pthread.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
